1. Field of the Invention
The invention relates to a wiring board, an electronic component mounting structure, and an electronic component mounting method for mounting electronic components. In particular, the invention relate to improving the accuracy of positioning of electronic components in an electronic component mounting structure and an electronic component mounting method.
2. Description of the Related Art
Recently, electronic devices such as computers, cellular phones, and personal digital assistants (PDAs) have been miniaturized, sophisticated, and speeded up. Further minaturization, higher speeds, and higher densities have thus been required of semiconductor apparatuses that incorporate ICs (integrated circuits), LSIs (Large-Scale ICs), and other semiconductor chips intended for use in such electronic devices. With the miniaturization and increasing density of these semiconductor apparatuses, a flip chip mounting method has been increasingly used where semiconductor chips are provided with protruding electrodes and are surface mounted onto a wiring board with their protruding electrode sides facing downward (see Japanese Patent Laid-Open Publication No. Hei 09-246319).
In the conventional flip chip mounting structure and method, the possibility has existed that slight displacement of semiconductor chips placed on a wiring board creates solder contacts or bridges between adjoining bumps when the bumps are formed at smaller spacings. This slight displacement has produced problems such that it has been difficult to miniaturize the semiconductor apparatuses, and that semiconductor apparatus manufacturing yields have therefore dropped.